The present application claims the priority of Japanese Patent Application No. 2002-298347 filed on Oct. 11, 2002, which application is incorporated herein by reference.
1. Technical Field
The invention relates to the improvement of a metallic vapor deposition lens adopted for the spectacle lens and the sunglasses and the production method of the same, in more details, pertaining to such metallic vapor deposition lens provided with a protection coat as being smooth on the surface and excelling in abrasion-proof characteristic and the production method of the same lens.
2. Prior Art
As known, a polarized lens is generally adopted for the sunglasses, which polarized lens is arranged by attaching a polarized film on the glasses and one example of which is disclosed in Japanese Patent Application Laid-open No. 2001-350122 (refer to Pages 3 through 5 and FIGS. 1 through 3).
The recent progress of the lens processing technique leads to the development of a high-performance metallic vapor deposition lens wherein a metallic material is attached on the outer surface of the lens by vapor deposition so as to reflect visible light, which lens is especially popular among the users where being finished with a lustrous touch.
However, such metallic vapor deposition lens as mentioned above is poor at abrasion-proof characteristic so that the metallic deposition layer is easily peeled off by an inadvertent contact therewith. Thus, due care should be taken to handle the same.
Under such circumstances as mentioned above, in order to protect the metallic deposition layer, conventionally, the method of dipping the lens into the fused resin material is known, which method causes the non-uniform attachment of the resin coat on the lens surface owing to the viscosity-related unbalanced spreading of the fused resin material thereon. This unavoidably causes the inconsistency of the attached resin coat on the finished lens surface, which results in the appearance of the wavy patterns with rainbow colors on the surface owing to the difference in thickness of the attached resin coat and the interference of the visible light. This gives a strange look on the wearer""s face.
In view of the above inconveniences encountered with the prior metallic vapor deposition lens, the invention is to provide a metallic vapor deposition lens provided with a protection coat that is smooth on the surface and excels in abrasion-proof characteristic.
The invention is further to provide a method of efficiently and economically producing a metallic vapor deposition lens provided with a protection coat that is smooth on the surface and excels in abrasion-proof characteristic, which protection coat is made of a casting resin essentially consisting of diethylene glycol bis(allyl carbonate) characteristic in lower viscosity and higher ductility.
Namely, in order to solve the above issues, the metallic vapor deposition lens provided with a protection coat according to the invention is characterized in that a vapor deposition filmy layer 2 made from a metallic material m is formed on at least one side surface of a lens proper 1 and a polymerization hardening layer 3 made from diethylene glycol bis (allyl carbonate) is overlaid on the filmy layer 2 so as to protect the surface of the vapor deposition filmy layer 2.
Further, the above metallic vapor deposition lens is characterized in that the polymerization hardening layer 3 overlaid on the surface of the vapor deposition filmy layer 2 has approximately 0.1 mm in thickness.
Further, the above metallic vapor deposition lens is characterized in that the lens proper 1 is made from a polycarbonate resin material.
Furthermore, the above metallic vapor deposition lens is characterized in that the metallic material m of the vapor deposition layer 2 comprises either a sole component or combined components selected from the group consisting of chromium, chromiumoxide, siliconedioxide, zirconium dioxide, titanium dioxide, alumina and gold.
Moreover, the above metallic vapor deposition lens is characterized in that the whole lens including the lens proper 1 and the polymerization hardening layer 3 is laminated by a hardening coat 4.
Then, the method of producing a metallic vapor deposition lens provided with a protection coat according to the invention is characterized in comprising the steps of placing a lens proper 1 in a vacuum chamber V and depressurizing the chamber; vaporizing a metallic material m in the chamber as depressurized by means of a heating means and filming the metallic material as vaporized on a convex surface of the lens proper 1 so as to form a metallic deposition filmy layer 2; dropping a casting resin R of lower viscosity essentially consisting of diethylene glycol bis(allyl carbonate) into a casting die D provided with a concave cavity C corresponding to a concave surface of the lens proper 1; placing the metallic deposition filmy layer 2 formed on the convex surface of the lens proper 1 as taken out of the vacuum chamber V on a concave surface of the cavity C so as to uniformly spread and attach the casting resin R on the metallic deposition filmy layer 2 and polymerizing and hardening the casting resin R as spread under heating treatment; and taking out an integral lens prototype Lb from the casting die D and subjecting the lens prototype to finishing treatment so as to produce the metallic vapor deposition lens provided with a protection coat L.
Further, the above method of producing a metallic vapor deposition lens is characterized in adjusting an input amount of the casting resin R such that the resin R is increased so as to form a polymerized hardening layer 3 of larger thickness on a convex surface of the metallic deposition filmy layer 2.
Furthermore, the above method of producing a metallic vapor deposition lens is characterized in laminating a hardening coat on the whole surface of the lens L as subjected to the finishing treatment.